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1.
Biol Pharm Bull ; 46(7): 1024-1026, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37394634

RESUMO

It is necessary to evaluate the efficiency of reduction for cyanide and cyanoglycosides during the manufacturing process from raw material beans to sweetened bean paste in a food hygiene control system from the viewpoint of food safety. Analytical methods for cyanide and cyanoglycoside determination in sweetened bean paste by HPLC with fluorescence detection were developed. In analysis of collection time of free cyanide in the free cyanide assay, the recovery was improved by extending the collection time, the recovery rate was >80% by 2 h. The accuracy, repeatability and intra-laboratory precision of the free cyanide assay were 82.3, 2.0, and 2.4%, respectively. The method for cyanoglycoside analysis was evaluated by 5 repeated spiked recovery experiments at a concentration of 10 ppm. The accuracy, repeatability and intra-laboratory precision of the cyanoglycoside method were 82.2, 1.9, and 3.4%, respectively. These analytical methods will enable the analysis of cyanide and cyanoglycosides in sweetened bean paste without using steam distillation method in the pretreatment.


Assuntos
Cianetos , Cianetos/análise , Cromatografia Líquida de Alta Pressão
2.
Curr Microbiol ; 79(8): 217, 2022 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-35704076

RESUMO

Gentamicin is an important antibiotic for the treatment of opportunistic infections in the clinical field. Gentamicin-resistant bacteria have been detected in livestock animals and can be transmitted to humans through the food supply or direct contact. We have previously revealed that gentamicin-resistant Escherichia coli are distributed at a comparatively high rate from beef cattle in Japan, but few studies have focused on the molecular epidemiology of gentamicin-resistant bacteria. To understand these bacteria, this study examined the prevalence of various gentamicin resistance genes in gentamicin-resistant E. coli isolates from beef cattle feces. Of the 239 gentamicin-resistant E. coli isolates, the presence of the aacC2, aadB, or aac(3)-VIa genes was confirmed in 147, 84, and 8 isolates, respectively. All aac(3)-VIa-harboring isolates had an MIC value of 64 µg/mL for gentamicin and exhibited resistance to 11 antibiotic agents. An analysis of the representative aac(3)-VIa-harboring E. coli strain GC1-3-GR-4 revealed that the aac(3)-VIa gene was present on the IncA/C plasmid together with the aadA and blaCMY genes. Furthermore, the upstream region of the aac(3)-VIa gene contained the aadA gene and the class 1 integron-integrase gene (intI1). The aac(3)-VIa gene was detected for the first time in Japan and is expected to be able to transfer between bacteria via the IncA/C plasmid and integron. These results reveal the expansion of the distribution or diversity of gentamicin resistance genes in Japan.


Assuntos
Infecções por Escherichia coli , Escherichia coli , Animais , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Bovinos , Escherichia coli/genética , Infecções por Escherichia coli/tratamento farmacológico , Infecções por Escherichia coli/epidemiologia , Infecções por Escherichia coli/veterinária , Fezes/microbiologia , Gentamicinas/farmacologia , Japão/epidemiologia , Testes de Sensibilidade Microbiana , Prevalência
3.
Shokuhin Eiseigaku Zasshi ; 63(5): 190-194, 2022.
Artigo em Japonês | MEDLINE | ID: mdl-36328475

RESUMO

Ciguatera fish poisoning (CFP) is recognized as the most frequent seafood poisoning due to the consumption of fish containing the principal toxins, ciguatoxins (CTXs). In Japan, CFP events have been reported annually from Okinawa and Amami Islands, locating subtropical regions. In addition, there have been reported several outbreaks due to consumption of the fish caught from the Pacific coast of the Mainland and they were often caused by the matured spotted knifejaw, Oplegnathus punctatus. As part of our research on CFP in Japan, we investigated CTXs analysis by LC-MS/MS on 176 individuals of O. punctatus (weight: 100-6,350 g, standard length: 13-60 cm) from the coast of the Mainland (Honshu, Shikoku, and Kyushu), Amami, Okinawa, and Ogasawara (Bonin) Islands. CTXs were detected from only two specimens collected from Okinawa. Total CTXs levels of the two specimens were at 0.014 and 0.040 µg/kg, respectively, exceeding FDA guidance level at 0.01 µg CTX1B equivalent/kg. However, they might be little risk of CFP because consuming over 1.5 kg of flesh is needed to develop intoxication. The toxins consisted of CTX1B analogs including CTX1B, 52-epi-54-deoxyCTX1B, CTX4A, and CTX4B, and no CTX3C analogs, supporting the finding that ciguatoxic fishes in Okinawan Waters containing only CTX1B analogs.


Assuntos
Ciguatera , Ciguatoxinas , Animais , Ciguatoxinas/toxicidade , Ciguatoxinas/análise , Cromatografia Líquida , Japão , Espectrometria de Massas em Tandem , Ciguatera/epidemiologia , Ciguatera/etiologia , Peixes
4.
Bioorg Med Chem Lett ; 43: 128052, 2021 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-33887440

RESUMO

Ciclesonide is an inhaled corticosteroid used to treat asthma and is currently undergoing clinical trials for treatment of coronavirus disease 2019 (COVID-19). An active metabolite of ciclesonide, Cic2, was recently reported to repress severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) genomic RNA replication. Herein, we designed and synthesized a few types of ciclesonide analogues. Cic4 (bearing an azide group) and Cic6 (bearing a chloro group) potently decreased SARS-CoV-2 viral replication and had low cytotoxicity compared with Cic2 (bearing a hydroxy group). These compounds are promising as novel therapeutic agents for COVID-19 that show significant antiviral activity.


Assuntos
Tratamento Farmacológico da COVID-19 , Pregnenodionas/farmacologia , RNA Viral/antagonistas & inibidores , SARS-CoV-2/efeitos dos fármacos , COVID-19/virologia , Glucocorticoides/farmacologia , Humanos , RNA Viral/genética , SARS-CoV-2/genética , Replicação Viral/genética
5.
Curr Microbiol ; 78(1): 265-273, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33095293

RESUMO

This study investigated the genetic and pathogenic variation of the subgroups of clade 2 strains of Shiga toxin (Stx)-producing Escherichia coli (STEC) O157. A total of 111 strains of STEC O157 isolated in Shimane prefecture, Japan, were classified in clade 2 (n = 39), clade 3 (n = 16), clade 4/5 (n = 3), clade 7 (n = 14), clade 8 (n = 17), and clade 12 (n = 22) by single-nucleotide polymorphism analysis and lineage-specific polymorphism assay-6. These results showed a distinct difference from our previous study in which clade 3 strains were the most prevalent strains in three other prefectures in Japan, indicating that the clade distribution of O157 strains was different in different geographic areas in Japan. Phylogenetic analysis using insertion sequence (IS) 629 distribution data showed that clade 2 strains formed two clusters, designated 2a and 2b. Stx2 production by cluster 2b strains was significantly higher than by cluster 2a strains (P < 0.01). In addition, population genetic analysis of the clade 2 strains showed significant linkage disequilibrium in the IS629 distribution of the strains in clusters 2a and 2b (P < 0.05). The ΦPT values calculated using the IS629 distribution data indicated that strains in clusters 2a and 2b were genetically different (P < 0.001). Cluster 2b strains are a highly pathogenic phylogenetic group and their geographic spread may be a serious public health concern.


Assuntos
Infecções por Escherichia coli , Escherichia coli O157 , Infecções por Escherichia coli/epidemiologia , Escherichia coli O157/genética , Humanos , Japão , Filogenia , Prevalência , Toxinas Shiga
6.
Shokuhin Eiseigaku Zasshi ; 62(5): 157-161, 2021.
Artigo em Japonês | MEDLINE | ID: mdl-34732641

RESUMO

Ciguatera poisoning (CP) is one of the most abundant seafood poisonings in the world. CP frequently occurred in the tropical and subtropical Indo-Pacific Ocean and the Caribbean Sea. In Japan, CP cases have been reported annually, from the subtropical regions, including Okinawa Prefecture and Amami Islands, Kagoshima Prefecture. The principal toxins, named ciguatoxins (CTXs), are bio-synthesized by benthic dinoflagellate of genera Gambierdiscus and Fukuyoa. They are bio-transferred herbivorous animals to carnivorous fishes via the food chain.The Ogasawara Islands comprise more than 30 islands, Mukojima Islands, Chichijima (Bonin) Islands, Hahajima Islands, Iwo Islands, Nishinoshima, Minamitorishima, and Okinotorishima, which locate in the tropical to subtropical regions. The Mukojima Islands, Chichijima Islands, and Hahajima Islands locate approximately the same latitude as Okinawa. The distance from Tokyo is approximately 1,000 km for Chichijima, 1,700 km for Okinotorishima (the southernmost tip of Japan), and 1,900 km for Minamitorishima (the easternmost tip of Japan). These islands exist in a wide range of waters, latitudes from 20°25' to 27°44' North and longitudes from 136°04' to 153° 59' East. We collected 65 specimens of a grouper, Variola louti, the most frequent species implicated in CP in Japan, from the waters around the Chichijima, Mukojima, and Hahajima islands. The fish flesh specimens were analyzed CTXs using the liquid chromatography-tandem mass spectrometer (LC-MS/MS). While the peak whose retention time is almost identical to that of CTX1B was detected in all specimens on our routine protocol, no 52-epi-54-deoxyCTX1B nor 54-deoxyCTX1B was detected. The peak retention time was quite different from that of CTX1B when re-analyzing by changing the analytical column. Thus, the CTXs in the specimens in the waters of these islands seemed to be undetectable levels.


Assuntos
Bass , Ciguatera , Ciguatoxinas , Varíola , Animais , Cromatografia Líquida , Ciguatera/epidemiologia , Ciguatoxinas/análise , Peixes , Ilhas , Japão , Espectrometria de Massas em Tandem
7.
Shokuhin Eiseigaku Zasshi ; 62(1): 8-13, 2021.
Artigo em Japonês | MEDLINE | ID: mdl-33658463

RESUMO

Ciguatera fish poisoning (CFP), one of the most frequently occurring seafood poisonings due to marine finfish consumption, mainly affects the tropical and subtropical Indo-Pacific region and the Caribbean Sea. The principal class of toxins, ciguatoxins (CTXs) from the Pacific, includes more than 20 derivatives and are classified into two groups, CTX1B and CTX3C congeners, based on their skeletal structures. As part of risk management of CFP by the Japanese government, the import of certain species of fish into Japan is prohibited. Additionally, local governments recommend rejecting certain fish species caught in Japan. In this study, we used LC-MS/MS to analyze CTXs from 18 fish specimens belonging to 7 species that had been brought to a wholesale market but were disapproved for sale because of their potential danger of CFP. CTXs were detected in four specimens of Lutjanus bohar and one specimen of Variola louti. It was estimated that the two most poisonous specimens (no. 5: 0.348 µg/kg, no. 8: 0.362 µg/kg) had a toxicity of 0.05 MU/g. Consumption of 200 g of flesh from these fish could cause CFP. Thus, the guidance of the local government to disallow the sale of these fish species in the market contributed to the prevention of CFP.Only CTX1B congeners were detected in L. bohar (specimen no. 5), which had no record of the area where it captured from. It is presumed that the origin of specimen no. 5 was the same as that of the Okinawan L. bohar because the CTX compositions were similar. In two specimens (nos. 6 and 8) from Wakayama, both CTX1B and CTX3C congeners were detected. This is the first report to reveal the CTX profile in fish collected off the Honshu island in Japan.


Assuntos
Ciguatera , Ciguatoxinas , Animais , Cromatografia Líquida , Ciguatera/epidemiologia , Ciguatera/etiologia , Ciguatoxinas/análise , Peixes , Japão , Espectrometria de Massas em Tandem
8.
Shokuhin Eiseigaku Zasshi ; 61(4): 126-131, 2020.
Artigo em Japonês | MEDLINE | ID: mdl-33012766

RESUMO

Campylobacter is one of the most important causes of food-borne infectious diseases. Antibiotics are rarely needed to treat campylobacteriosis, but occasionally used in severe or prolonged cases. Consumption of contaminated bovine liver is a source of campylobacteriosis. Bovine liver can be contaminated with Campylobacter on the surface and inside by the bile at slaughterhouses. Therefore, we investigated the current prevalence and characteristics of Campylobacter in bovine bile at a slaughterhouse. Campylobacter was isolated from 35.7% (55/154) of bile samples. C. jejuni and C. fetus were the two most frequent species. High antimicrobial resistant rates in C. jejuni were observed against tetracycline (63.0%) and ciprofloxacin (44.4%). Multi-locus sequence typing divided C. jejuni isolates (27 isolates) into 12 sequence types (STs) in which ST806 was the most frequent ST and accounted for 37.0%. All C. fetus were identified as C. fetus subsp. fetus which can cause systemic infections. High antimicrobial resistant rates in C. fetus were observed against ciprofloxacin (66.6%), streptomycin (58.3%) and tetracycline (33.3%). All the C. fetus isolates were divided into two STs, ST3 (16 isolates) and ST6 (8 isolates). Of the 16 ST3 isolates, 15 (93.8%) were resistant to both streptomycin and ciprofloxacin. Our data shows high prevalence of Campylobacter in bovine bile and their high rates of antimicrobial resistance. Preventing bile contamination of bovine liver at slaughterhouses is thus considered to be one of control measures to reduce the risk of Campylobacter infections.


Assuntos
Bile , Campylobacter , Vesícula Biliar , Animais , Anti-Infecciosos/farmacologia , Bile/microbiologia , Campylobacter/classificação , Campylobacter/efeitos dos fármacos , Campylobacter/genética , Campylobacter/isolamento & purificação , Bovinos , Farmacorresistência Bacteriana , Microbiologia de Alimentos , Vesícula Biliar/microbiologia , Tipagem de Sequências Multilocus , Prevalência
9.
Shokuhin Eiseigaku Zasshi ; 61(4): 103-108, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33012763

RESUMO

Ascaris lumbricoides or roundworm is one of the key soil-transmitted helminths affecting humans. A small number of infections continue to occur in Japan, suggesting plant foodstuff contamination as the source of infection. To understand the current status of ascariasis incidence and to identify potential sources of infection, we extensively surveyed the available literature and collected data from testing facilities that examined clinical samples or foodstuffs. We observed that from 2002 onwards, there was a decrease in the number of ascariasis cases reported in scientific journals. Data from a clinical testing facility indicated that the number of detected cases declined remarkably from 2009. Foodstuff testing facilities reported that 11 of 10,223 plant foodstuff specimens were contaminated with anisakid nematodes but not with Ascaris. Imported kimchi was suspected as the most probable source of ascarid nematode infection, as one Ascaris egg-positive sample was detected among 60 kimchi samples in a testing facility. Therefore, the sources of Ascaris infection are still not fully known and need to be clarified to establish preventive countermeasures to safeguard Ascaris infections that continue to occur in Japan.


Assuntos
Ascaríase , Ascaris lumbricoides , Parasitologia de Alimentos , Animais , Ascaríase/epidemiologia , Ascaríase/prevenção & controle , Humanos , Incidência , Japão/epidemiologia , Solo
10.
Ann Clin Microbiol Antimicrob ; 16(1): 61, 2017 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-28923072

RESUMO

BACKGROUND: Botulism is a potentially fatal infection characterized by progressive muscle weakness, bulbar paralysis, constipation and other autonomic dysfunctions. A recent report suggested that cancer chemotherapy might increase the risk for the intestinal toxemia botulism in both adults and children. CASE PRESENTATION: We report a 5-year-old boy, who developed general muscle weakness, constipation, ptosis and mydriasis during the third induction therapy for relapsed acute myeloid leukemia. He had recent histories of multiple antibiotic therapy for bacteremia and intake of well water at home. Repeated bacterial cultures identified Clostridium botulinum producing botulinum neurotoxin A. Botulinum toxin A was isolated from his stools at 17, 21, and 23 days after the onset. Symptoms were self-limiting, and were fully recovered without anti-botulinum toxin globulin therapy. CONCLUSION: This is the second report of a pediatric case with cancer chemotherapy-associated intestinal toxemia botulism. Our case provides further evidence that the immunocompromised status due to anti-cancer treatments increases the risk for the development of botulism at all ages in childhood.


Assuntos
Botulismo/complicações , Clostridium botulinum/patogenicidade , Intestinos/microbiologia , Leucemia/complicações , Leucemia/tratamento farmacológico , Toxemia/complicações , Antibacterianos/farmacologia , Bacteriemia/tratamento farmacológico , Infecções Bacterianas , Toxinas Botulínicas , Toxinas Botulínicas Tipo A/isolamento & purificação , California , Pré-Escolar , Clostridium botulinum/isolamento & purificação , Clostridium botulinum/metabolismo , Tratamento Farmacológico , Fezes/química , Fezes/microbiologia , Humanos , Masculino , Doenças Raras
11.
Environ Microbiol ; 17(11): 4779-89, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26373338

RESUMO

Multicellular biofilms are an ancient bacterial adaptation that offers a protective environment for survival in hostile habitats. In microaerophilic organisms such as Campylobacter, biofilms play a key role in transmission to humans as the bacteria are exposed to atmospheric oxygen concentrations when leaving the reservoir host gut. Genetic determinants of biofilm formation differ between species, but little is known about how strains of the same species achieve the biofilm phenotype with different genetic backgrounds. Our approach combines genome-wide association studies with traditional microbiology techniques to investigate the genetic basis of biofilm formation in 102 Campylobacter jejuni isolates. We quantified biofilm formation among the isolates and identified hotspots of genetic variation in homologous sequences that correspond to variation in biofilm phenotypes. Thirteen genes demonstrated a statistically robust association including those involved in adhesion, motility, glycosylation, capsule production and oxidative stress. The genes associated with biofilm formation were different in the host generalist ST-21 and ST-45 clonal complexes, which are frequently isolated from multiple host species and clinical samples. This suggests the evolution of enhanced biofilm from different genetic backgrounds and a possible role in colonization of multiple hosts and transmission to humans.


Assuntos
Biofilmes/crescimento & desenvolvimento , Campylobacter jejuni/genética , Patrimônio Genético , Variação Genética/genética , Evolução Biológica , Campylobacter jejuni/classificação , Campylobacter jejuni/isolamento & purificação , Estudo de Associação Genômica Ampla , Humanos , Oxigênio/metabolismo
12.
Cell Microbiol ; 15(11): 1896-912, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23782461

RESUMO

Helicobacter pylori is a bacterial pathogen that colonizes the gastric niche of ∼ 50% of the human population worldwide and is known to cause peptic ulceration and gastric cancer. Pathology of infection strongly depends on a cag pathogenicity island (cagPAI)-encoded type IV secretion system (T4SS). Here, we aimed to identify as yet unknown bacterial factors involved in cagPAI effector function and performed a large-scale screen of an H. pylori transposon mutant library using activation of the pro-inflammatory transcription factor NF-κB in human gastric epithelial cells as a measure of T4SS function. Analysis of ∼ 3000 H. pylori mutants revealed three non-cagPAI genes that affected NF-κB nuclear translocation. Of these, the outer membrane protein HopQ from H. pylori strain P12 was essential for CagA translocation and for CagA-mediated host cell responses such as formation of the hummingbird phenotype and cell scattering. Besides that, deletion of hopQ reduced T4SS-dependent activation of NF-κB, induction of MAPK signalling and secretion of interleukin 8 (IL-8) in the host cells, but did not affect motility or the quantity of bacteria attached to host cells. Hence, we identified HopQ as a non-cagPAI-encoded cofactor of T4SS function.


Assuntos
Proteínas da Membrana Bacteriana Externa/metabolismo , Sistemas de Secreção Bacterianos , Helicobacter pylori/metabolismo , Fatores de Virulência/metabolismo , Proteínas da Membrana Bacteriana Externa/genética , Linhagem Celular , Elementos de DNA Transponíveis , Células Epiteliais/microbiologia , Deleção de Genes , Helicobacter pylori/genética , Helicobacter pylori/patogenicidade , Humanos , Interleucina-8/metabolismo , Quinases de Proteína Quinase Ativadas por Mitógeno/metabolismo , Dados de Sequência Molecular , Mutagênese Insercional , NF-kappa B/metabolismo , Análise de Sequência de DNA , Transdução de Sinais , Fatores de Virulência/genética
13.
PeerJ ; 12: e17207, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38618566

RESUMO

Long-term microplastics (MPs) environmental pollution trends cannot be understood only by investigating their presence on beaches. Without estimating MPs for the entire beach, comparisons between multiple beaches cannot be made. In this study, Nagasaki Prefecture was selected as the study site, we measured MPs accumulation rate to express the MPs pollution trend and weighted the measurement results to enable comparison of MPs content among multiple sandy beaches. The MPs accumulation rate in the study site was measured by periodic investigation at fixed spots. The average in the supratidal zone was 1.5 ± 0.9 mg-MPs/(m2-sand⋅ d) (n = 15). The weighting of the MPs content in hot spots and non-hot spots by their respective areas enabled us to obtain the representative value and the dispersion of the MPs content in the entire study site. The MPs contents in the three beaches were 298 ± 144, 1,115 ± 518, and 4,084 ± 2,243 mg-MPs/(m2-sand), respectively. Using these values, it is possible to compare the MPs contents of multiple beaches.


Assuntos
Dermatite , Microplásticos , Humanos , Plásticos , Poluição Ambiental , Areia
14.
Folia Microbiol (Praha) ; 69(2): 347-360, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37405631

RESUMO

The populations of Japanese deer and boar have increased dramatically and have a serious impact on farming and mountain villages. Although the Japanese government promotes the use of captured wild animals, game meat is not subject to sanitary control considering that it is not subject to meat inspection or quality control. Here, we have attempted to isolate Staphylococcus aureus, a typical foodborne pathogen, as a part of an investigation of contamination in the meats of wild animals and their processing stages. We examined 390 samples of deer feces, 117 samples of wild boar feces, and 75 samples of disemboweled deer meat for isolation of S. aureus; ultimately, 30 (positive rate: 7.7%), 2 (1.7%), and 21 (28.0%) strains were isolated, respectively, from the samples. The genome sequences of these isolates were analyzed and were subjected to multilocus sequence typing. We identified 12 new sequence types (STs) and a dominant population of S. aureus with a characteristic genetic background in wild animals, namely, the ST groups derived from CC121 (number of strains = 39). These strains did not harbor the enterotoxin gene or only harbored egc-related enterotoxin, which is of low involvement in Staphylococcal food poisoning. However, one ST2449 strain, which produces causative enterotoxins, was isolated from a deer's feces. Since there are several common STs isolated from feces and dismembered meat and because fecal contamination during dismemberment is suspected, continuous monitoring and guidance for improving sanitary management conditions during processing and handling of the meat are highly warranted with immediate effect.


Assuntos
Cervos , Infecções Estafilocócicas , Animais , Suínos , Staphylococcus aureus/genética , Animais Selvagens , Enterotoxinas/genética , Infecções Estafilocócicas/epidemiologia , Carne , Fezes , Microbiologia de Alimentos
15.
J AOAC Int ; 96(5): 991-7, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24282937

RESUMO

For the surveillance of the prevalence of Campylobacter jejuni and Campylobacter coli in raw chicken products in Japan, a qualitative method, National Institute of Health Sciences Japan (NIHSJ)-02, was developed as an alternative to International Organization for Standardization (ISO) 10272-1:2006. In the NIHSJ-02 culture method, the enrichment step is carried out in a reduced volume of Preston broth at 42 +/- 1 degrees C to reduce cost and space, and to prevent the overgrowth of background bacteria. To evaluate the performance of NIHSJ-02, a collaborative study was conducted, and the results obtained by NIHSJ-02 were compared with those obtained using the reference method, ISO 10272-1:2006. Fifteen laboratories participated; each examined 48 minced chicken samples consisting of test samples uninoculated, inoculated with C. jejuni at a low or high level, and inoculated with C. coli at a low level. The average probabilities of detection by NIHSJ-02 across laboratories were 0.033, 0.222, 0.678, and 0.267 in samples uninoculated, inoculated with C. jejuni at a low and high level, and with C. coli at a low level, respectively. Those by ISO 10272-1:2006 were 0.051, 0.128, 0.551, and 0.090. Significantly higher probabilities of detection were determined by NIHSJ-02 compared to ISO 10272-1:2006, except for uninoculated samples. On the other hand, significantly lower frequency of occurrence of background bacteria was observed by NIHSJ-02 (43.1%) compared with ISO 10272-1:2006 (92.6%). NIHSJ-02 showed better performance than ISO 10272-1:2006 with regard to the selective detection of C. jejuni and C. coli in chicken.


Assuntos
Campylobacter coli/isolamento & purificação , Campylobacter jejuni/isolamento & purificação , Galinhas/microbiologia , Animais , Comportamento Cooperativo , Meios de Cultura , Microbiologia de Alimentos
16.
J Environ Sci (China) ; 25(1): 53-8, 2013 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-23586299

RESUMO

Landfilling municipal solid waste incineration (MSWI) residue alkalizes the waste layer, causing a subsequent decrease in microbial activity and a delay in the decomposition of organic matter. In this study, efficiencies of neutralization of the leachate and organic matter decomposition in the waste layer in a column filled with MSWI residue using aeration and compost addition were evaluated. Total organic carbon (TOC) reduction in the waste layer is large at high oxygen flow rate (OFR). To effectively accelerate TOC reduction in the waste layer to which compost was added, a high OFR exceeding that by natural ventilation was required. At day 65, the pH of the leachate when OFR was above 10(2) mol-O2/(day x m3) was lower than that when OFR was below 10(1) mol-O2/(day x m3). At the same OFR, the pH of waste sample was lower than that of waste sample with compost. Although leachate neutralization could be affected by compost addition, TOC reduction in the waste layer became rather small. It is possible that humic substances in compost prevent the decomposition of TOC in MSWI residue.


Assuntos
Incineração , Oxigênio , Eliminação de Resíduos , Concentração de Íons de Hidrogênio , Solo
17.
Microb Genom ; 9(10)2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37850975

RESUMO

Listeria monocytogenes is an opportunistic food-borne bacterium that is capable of infecting humans with high rates of hospitalization and mortality. Natural populations are genotypically and phenotypically variable, with some lineages being responsible for most human infections. The success of L. monocytogenes is linked to its capacity to persist on food and in the environment. Biofilms are an important feature that allow these bacteria to persist and infect humans, so understanding the genetic basis of biofilm formation is key to understanding transmission. We sought to investigate the biofilm-forming ability of L. monocytogenes by identifying genetic variation that underlies biofilm formation in natural populations using genome-wide association studies (GWAS). Changes in gene expression of specific strains during biofilm formation were then investigated using RNA sequencing (RNA-seq). Genetic variation associated with enhanced biofilm formation was identified in 273 genes by GWAS and differential expression in 220 genes by RNA-seq. Statistical analyses show that the number of overlapping genes flagged by either type of experiment is less than expected by random sampling. This novel finding is consistent with an evolutionary scenario where rapid adaptation is driven by variation in gene expression of pioneer genes, and this is followed by slower adaptation driven by nucleotide changes within the core genome.


Assuntos
Listeria monocytogenes , Listeria , Humanos , Listeria/genética , Estudo de Associação Genômica Ampla , Biofilmes , Listeria monocytogenes/genética
18.
Biochem Biophys Res Commun ; 426(4): 654-8, 2012 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-22975346

RESUMO

Salmonella enterica serovar Typhimurium is a major cause of human gastrointestinal illness worldwide. This pathogen can persist in a wide range of environments, making it of great concern to public health. Here, we report that the salmonella pathogenicity island (SPI)-1 effector protein SipB exhibits a membrane topology that confers bacterial osmotolerance. Disruption of the sipB gene or the invG gene (SPI-1 component) significantly reduced the osmotolerance of S. Typhimurium LT2. Biochemical assays showed that NaCl osmolarity increased the membrane topology of SipB, and a neutralising antibody against SipB reduced osmotolerance in the WT strain. The WT strain, but not the sipB mutant, exhibited elevated cyclopropane fatty acid C19:0 during conditions of osmotic stress, correlating with the observed levels of survival and membrane integrity. This result suggests a link between SipB and the altered fatty acid composition induced upon exposure to osmotic stress. Overall, our findings provide the first evidence that the Salmonella virulence translocon SipB affects membrane fluidity and alters bacterial osmotolerance.


Assuntos
Proteínas de Bactérias/química , Membrana Celular/química , Proteínas de Membrana/química , Infecções por Salmonella/microbiologia , Salmonella typhimurium/patogenicidade , Proteínas de Bactérias/genética , Ácidos Graxos/análise , Ilhas Genômicas/genética , Humanos , Fluidez de Membrana , Proteínas de Membrana/genética , Osmose , Pressão Osmótica , Cloreto de Sódio/química , Virulência
19.
Microbiol Immunol ; 56(4): 228-37, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22256797

RESUMO

In stressful conditions, bacteria enter into the viable but non-culturable (VBNC) state; in this state, they are alive but fail to grow on conventional media on which they normally grow and develop into colonies. The molecular basis underlying this state is unknown. We investigated the role of the alternative sigma factor RpoS (σ(38)) in the VBNC induction using Salmonella Dublin, Salmonella Oranienburg and Salmonella Typhimurium LT2. VBNC was induced by osmotic stress in LT2 and Oranienburg. Dublin also entered the VBNC state, but more slowly than LT2 and Oranienburg did. The LT2 rpoS gene was initiated from an alternative initiation codon, TTG; therefore, LT2 had smaller amounts of RpoS than Dublin and Oranienburg. Oranienburg had a single amino acid substitution (D118N) in RpoS (RpoS(SO)). Disruption of rpoS caused rapid VBNC induction. VBNC induction was significantly delayed by Dublin-type RpoS (RpoS(SD)), but only slightly by RpoS(SO). These results indicate that RpoS delays VBNC induction and that the rapid induction of VBNC in LT2 and Oranienburg may be due to lower levels of RpoS and to the D118N amino acid substitution, respectively. Reduced RpoS intracellular level was observed during VBNC induction. During the VBNC induction, Salmonella might regulate RpoS which is important for maintenance of culturablity under stresses.


Assuntos
Proteínas de Bactérias/metabolismo , Regulação Bacteriana da Expressão Gênica , Salmonella enterica/fisiologia , Fator sigma/metabolismo , Estresse Fisiológico , Proteínas de Bactérias/genética , Técnicas de Inativação de Genes , Viabilidade Microbiana , Salmonella enterica/genética , Salmonella enterica/crescimento & desenvolvimento , Fator sigma/genética
20.
Nihon Rinsho ; 70(8): 1298-303, 2012 Aug.
Artigo em Japonês | MEDLINE | ID: mdl-22894062

RESUMO

Appropriate handling and controlled temperature prevent cross-contamination and proliferation of contaminants in foods, thereby reducing the incidences of food-borne gastroenteritis in Japan. However, the incidence of Campylobacter jejuni/coli infection did not markedly decrease and has become one of the major causes of food-borne diseases. C. jejuni and C. coli are widespread in warm-blooded domestic animals; therefore, food products may easily become contaminated during processing. C. jejuni and C. coli do not proliferate in foods, nor resistant to freezing, drying and oxidative stresses, and the number is greatly reduced under such conditions. These properties should be considered for risk management of Campylobacter in food processing and manufacturing.


Assuntos
Infecções por Campylobacter/epidemiologia , Infecções por Campylobacter/prevenção & controle , Doenças Transmitidas por Alimentos/epidemiologia , Doenças Transmitidas por Alimentos/prevenção & controle , Animais , Infecções por Campylobacter/microbiologia , Infecções por Campylobacter/fisiopatologia , Campylobacter coli/patogenicidade , Campylobacter jejuni/patogenicidade , Contaminação de Alimentos/prevenção & controle , Manipulação de Alimentos , Doenças Transmitidas por Alimentos/microbiologia , Doenças Transmitidas por Alimentos/fisiopatologia , Humanos , Japão/epidemiologia , Gestão de Riscos
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